Heat transfer resisting means for carburetors



March 26, 1946. w, WEBER I 2,397,392

HEAT .TRANSFER RESISTING MEANS FOR CARBURETORS Fi led Jan. 24, 1944INVENTOR.

Jvlv ATTORNEY Patented Mar. 26, 1946 UNITED STATES PATENT F FICE HEATTRANSFER'RESISTING' MEANS FOR CARBURETQRS Walt'enH. Weber, Detroit,Michl assi'gnori tmDetroit -'Lubricator: Company; Detroit, Mich,

\ corporation.- of -Michiganv Application January 24, 1944', Seriai'No."5193115 3 Claims.

This. invention relates to new andlusefuli improvements. in carburetorsfor supplying; fuel to an internal combustion engine.

In the operation of carburetors usinggasoline or other radiallyvaporizabl'e fuels, it may occur that the heat of the engine conductedto the carburetor float chamber will causethe fuel therein to boil,,andthus upset the. uniformrate. of supply of fuel to the mixing chamber. Insome cases, this will even cause a vapor lock preventing operation ofthe engine. It is, accordingly, the object of this invention toprovidelmeansto reducethe rate of. heat transfer from the engine. tothecarburetor fuel container or reservoirsufficiently so that vaporlocking andboiling. will not occur.

The invention consists i'ntheimproved. construction and combination ofparts. to be more fully described hereinafter and. the novelty of whichwill be particularly pointed out. anddiS- tinctly claimed.

In the accompanying drawing, to be taken. as. a part of thisspecification, there is fully and. clearly illustrated a preferredembodimentbi theinvention, in which drawing:

. Figure 1 is a view in vertical central section of a carburetorattached to an engine and having the heat transfer blocking means of theinvention;

Fig. 2 is a plan view of the outlet end portion of the carburetor;

Fig. 3 is a view in side elevation of the outlet end portion of thecarburetor, and

Fig. 4 is a view in section of the outlet end portion of the carburetor,taken on the line 4-4 oi Fig. 2.

Referring to the drawing by characters of reference, l designatesgenerally the body member of a carburetor having a mixture passageway 2with an air inlet 3 and an outlet 4. The member I is preferably a diecasting having integrally cast therewith a constant level fuel reservoir5 which, by reason of its rigid connection to the body member I, is inintimate heat exchange relation therewith. The reservoir 5 has the usualliquid inlet 6 for liquid fuel, such as gasoline. The liquid level inthe reservoir 5 is controlled by a float member 1 which is operativelyconnected to a valve 8 controlling flow into the reservoir 5 from theinlet 6. The reservoir 5 is connected to the mixture passageway 2 by afuel conduit 9 having a calibrated inlet port I0 below the reservoirliquid level. The conduit 9 has a portion H above the reservoir liquidlevel and has an outlet or nozzle l2 discharging into the passageway 2within the throat of a Venturi tube l3 positioned within the passageway2. The usual butterfly type throttle valve lllisprovided; to control thedischarge of fuel mixture. from" the carburetor outlet 4.

The outlet end, portion ofthe' passageway 2 is ,f-ormedjby a thinwall'tubul'ar conduit member 15 of. low heat, conducting'material, suchfor example .as stainless steel". The member l5 'flt'swithin aninternalv annular. end recess in the body membar I, and. has its innerendedge abutting. ashoulder, to. limit its inward. movement; The conduitmember I5 extend beyond or projects externally from the body'member land has its exterior end provided, an out-turned lateral flange Hi. The

.body, member I may, beprovidedwith legs or fins ll which, extendlongitudinally of the exterior portion of the memberl5 and back Orreinforce the. flange. l6. Surrounding the member l5 and projectinglaterally, from the outlet end portion block. l9 bya peripheral wall 2|which, together with; the plate, memb'er20}. provides an inverted I cuplike member having its rim, i. e. the edge of the wall 2| seating on theblock I9. Through the plate member20 there are air outlet apertures 22for discharge of air from the interior of the hollow flange. The wall 2!is provided with a plurality of apertures or slot openings 23 for theinflow of air to the interior of the 'hollow flange. The openings orapertures 22 and 23 cooperate to provide for cooling air flow throughthe hollow flange and in heat abstracting relation to the exteriorsurface of the projecting portion ofthe conduit member I5. The platemember 20 also has openings 24 therethrough positioned adjacent theflange wall l8 and in which are positioned bushings 25 of a length toextend flush with the flange I6 and also flush with, or slightly beyond,the rim of the Wall 2|. The bushings 25 are also each preferablyprovided with anend flange 26 which seats against and is backed byportions of the wall 2!. The bushings 25 are preferably of low heatconducting material, such as stainless steel, and receive bolts or studs21 which serve to clamp and secure the carburetor to the block l9.

It will be apparent from the foregoing description that the reservoir 5is protected against the conduction of engine heat through the walls ofthe body member I. Not only does the heat flow resisting member 15 cutdown the rate of heat conduction from the block l9, but in addition thismember I5 is cooled by air flow entering the hollow flange through theopenings 23 and discharging through the openings 22. This air flow, I

, 1. In a carburetor, a body member to 'be secured to an engine andhaving a mixturepassageway with an outlet for supplying a combustiblemixture to the engine, a liquid fuel reservoir carried an engineengaging edge, said flange Wall member surrounding and being spaced fromsaid con-v duit member and extending from the outer marginal edge ofsaid plate member and terminating in an engine engagin edge such thatsaid wall member, said plate member and said conduit 7 member provide achannel surroundin said conby and in heat exchange relation with saidbody member, a tubular thin wall conduit member of member and formingthe outlet portion of said passageway, a hollow flange extending fromsaid low heat conductivity extending from said body body member andsurrounding said conduit member, said flange comprising an aperturedlateral a carried by said passageway portion and communiplate member anda peripheral apertured wall member spaced laterally from and surroundinsaid conduit member and for abutting ehgagement with the engine tosupport said body member on the engine, the'apertures in said aperturedmembers providing inlets and outlets forair flow in cooling. relation tothe exterior of said conduit member, said plate member Lhaving'boltreceiving openings adjacent said wall member, a bushing jmember in eachopening and having a flange seatin again'stsaid wall member, saidconduit member having a flange in the plane of said bushing memberflanges, and reinforcing means extending from said plate member andbacking said conduit member flange.

2. In a carburetor, a body member having a passageway portion with amixture passageway and the outlet end of said passageway portion, and athin wall conduit member of relatively low heat conductivity fittingwithin said passageway and projecting from the outlet end of saidpassageway portion and beyond said plate member, said conduit memberhaving its outlet end'terminating in duitfmem'ben'said plate inemberfand said wall member each-having apertures therethrough for flow, ofcooling air through said channel to abistract heat from said flange andconduit member so as to resist conduction of engine heat to saidreservoir. 7

3. In a carburetor, a body member having a passageway portion witharmixture passageway and having ahollow flange for connection of thebody member to an engine, a liquid fuel reservoir 'catively connected tosaid passageway, said flange including a lateral plate member and aperipheral wallmember, said plate member extendin around the outletend'of said passageway portion, a thin wall conduit member of relativelylow heat conductivity fitting within said passageway and projecting fromthe outlet endof saidppassageway portion and beyond said plate member,said conduit member having its outlet end terminating in an annularsurrounding flange for engagement with the engine, said flange wallmember sur- 'member and projecting from said flange plate member intoabutting engagement With said conduit member flange,

WALTER I-I. WEBER.

